1. FIELD OF THE INVENTION
This invention relates to a common resource management method for a complex computer system in which resources are used commonly among a plurality of computers.
2. DESCRIPTION OF THE PRIOR ART
In a complex computer system including a plurality of computers, common resources are used commonly among these computers. The status of a common resource (e.g., setting of recording mediums, occupancy of data sets, etc.) has been managed by each computer individually. Each computer has tables for storing status information of the resources in its main storage or virtual memory so that access control to each resource is implemented using the status information.
This conventional resource management method has the following problems. When, a computer has set the status of a resource, it must indicate that status to other computers which share the resource. However, each computer has independent tables containing resource status information, and therefore the process is required for notifying other computers of the status information set by one computer. This notification is implemented by a unit called a channel-to-channel adapter (CTCA). Information transmitted to other computers indicates whether the resource is being used in the shared mode or exclusive mode, the volume serial number of the recording medium, the attribute of the volume and the like. Because of different means for sending each type of information, there is a need to provide a plurality of control means for respective types of information. A further problem is that frequent communication for the resource status information by the CTCA will adversely affect other data transfers which use the CTCA.